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Conference unifix::sailing

Title:	SAILING
Notice:	Please read Note 2.* before participating in this conference
Moderator:	UNIFIX::BERENS

Created:	Wed Jul 01 1992
Last Modified:	Mon Jun 02 1997
Last Successful Update:	Fri Jun 06 1997
Number of topics:	2299
Total number of notes:	20724

570.0. "Transoms vs LWL and LOA" by NRADM::MITCHELL () Tue Jun 09 1987 20:47

    I have a question w/regard to LOA & LWL
    
    While looking a assorted boats I see that some have standard
    Transoms, some Vertical and some Reverse. Most reverse transoms
    seem to be more the racing style while the verticals and standards
    appear to be geared to Cruising yachts.
    
    	My Question is this:
    
    Is the reverse transome a style,a gimmick(to make you think you
    have a bigger boat) or for esthetics. I figure that you can lose
    a couple of feet in the difference.
    
    I assume the LWL is very little affected by the extremes.
    
    				___GM___

T.R	Title	User	Personal Name	Date	Lines
570.1	a view	PULSAR::BERENS	Alan Berens	`Tue Jun 09 1987 21:29`	22
	With a reverse transom you obviously lose storage space (not a good thing if you are a cruiser). There will also be less reserve buoyancy aft, which will reduce load carrying ability and will likely have a bad effect in a big following sea. I would also think that a wave breaking against a reverse transom would be quite likely to slide right on into the cockpit. Lots of buoyancy aft would be nice when the cockpit fills with water. With a traditional transom the waterline length will increase as the boat heels. Not so with a reverse transom. On the other hand a boat with a reverse transom is likely to be lighter (good or bad depending on your viewpoint) and the mass of the hull will be closer to the center of boat (generally good). Aesthetically, I'm partial to the graceful sheers and longish overhangs of older, more tradtional boats (eg, the Hinckley Bermuda 40). Aesthetics aside, I suspect that the reverse transom is mostly the result of racing rule influence but also the result of builders seeking to differentiate their products. Alan
570.2	it's all theoretical...	ROCKET::HARDY		`Wed Jun 10 1987 12:01`	12
	I've always believed that the main reason for the reverse transom is: theoretical hull speed ~= (1.25 to 1.5) * SQRT (LWL) That is; the lwl is extended thereby increasing theoretical hull speed, yet, with very little increase in displacement. [Of course I'd rather be on that B40 to...] Gary H...
570.3	KIALOA in Newport	NRADM::MITCHELL		`Wed Jun 10 1987 14:59`	16
	Speaking of Transomes! My wife and I did a B&B in Newport about a month ago. A friend of mine has slip # 1 at the Pier restaurant. while I was there I noticed a HUGE racing yacht up on stilts being worked on...right across from the restaurant. The KIALOA...what a monster! The radical rear transom must have been about 6'. I also read recently that Kilroy, the owner, from LA just won the Class A international race in the KIALOA..could it have been the same boat? ___GM___
570.4	THE 80+ FOOT MAXI	MILVAX::BODGE		`Thu Jun 18 1987 17:04`	13
	IN RESPONSE TO 570.3..... 1. YES, THE BOAT YOU SAW WAS ONE IN THE SAME. THE MAXIS WERE IN NEWPORT RACING OVER THE LAST FEW WEEKS. I BELIEVE THAT THERE WAS A CONSIDERABLE TURN OUT FOR THE BIG BOATS. SOMEWHERE IN THE ORDER OF SEVEN OR EIGHT OF THOSE 80 FOOTERS. 2. MY UNDERSTANDING OF THE REVERSE TRANSOM IS IN LINE WITH THE OTHER RESPONSES. INCREASE THE LWL WITHOUT ADDING SIGNIFICANT WEIGHT, THEREBY INCREASING THEORETICAL HULL SPEED AND KEEPING THE WEIGHT OFF THE ENDS.